On Mon, Nov 25, 2013 at 7:30 AM, jb <jb.1234abcd@gmail.com> wrote:
Rodrigo Rivas <rodrigorivascosta <at> gmail.com> writes:
... The problem is in the "signal mask". It looks like some process masks the signals in the early boot, and then the signal mask is inherited by all the process in my session. And, as it seems, `gdb` needs a lot of signals to work properly, but it assumes that they are not masked at the beginning. I don't know if this should be considered a gdb bug or not, but the real problem is elsewhere. ... So I am now pretty sure that some process in the session is corrupting the signal mask. The only thing left is to know which one...
Review it: $ pstree -p
Your signal blocking could come from: - GUI Login Manager, DE session, ... Check for gnome-session PID and for its parent PID: $ grep SigBlk /proc/$pid/status - gnome-terminal (I guess) in which you run gdb Check as above.
This entry gives you an overview of signal states; it will help you match processes to e.g. SigBlk pattern: $ ps axs | grep fffffffe7ffbfeff
Btw, a similar problem occured there: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=499569
I think I've finally solved it! The first process in my session that gets the wrong signal mask is cinnamon-session, so that's where I started looking. I managed to trace the bug until the conection to logind via dbus. But the connection is made using glib/gio, so I looked there. Then I traced the glib code until a deep buried call to `pthread_create()`. That is in glibc! So I got the sources and debugged again. There things get complicated... The bug happens somewhere between glib calling pthread_create() and glibc's implementation of that very same function. I got a few stack traces and they all pointed to one suspect... /usr/lib/libnvidia-tls.so.331.20 Alas, the source of that file is not available, so my investigation ends here. I did a rollback to nvidia-325.15-11 and {nvidia-libgl,nvidia-utils,opencl-nvidia}-325.15-1 and all is back to normality 8-). A quick search in the web shows that it has happened before [1] [2] [3] I'm reporting my findings out there. To anybody that is still reading, thank you for you attention. -- Rodrigo. [1] https://devtalk.nvidia.com/default/topic/638521/linux/gnome-terminal-problem... [2] https://bugzilla.redhat.com/show_bug.cgi?id=1028272 [3] https://bbs.archlinux.org/viewtopic.php?pid=1350302